Experimental Demonstration of Nonlinear Scattering Processes in a Microbottle Resonator Based on a Robust Packaged Platform

Microbottle resonators (MBR) have attracted research interest for studying nonlinear optical interactions in last two decades, due to the ultra-tight optical confinement in spaces of three dimensions. In this paper, silica MBRs exhibiting rich resonant modes with ultra-high quality factor up to
$3.73 \times {10^8}$
are demonstrated, based on which a portable and robust packaged platform with a tapered fiber coupling is established. Such a packaged platform effectively avoids external perturbations such as air flow and tiny mechanical vibrations, which supports our experimental demonstration of nonlinear scattering effects including four-wave mixing (FWM), simulated Raman scattering, and simulated Brillouin scattering. As a result, Raman-assisted FWM and Brillouin-assisted FWM are observed due to the strong field enhancement in the MBR. In a further investigation, a Kerr frequency comb with broad bandwidth of ∼200 nm and a Raman-assisted comb with a bandwidth up to ∼50 nm is achieved, correspondingly. Our works show the versatility of MBR for fundamental research and may open a new route to the development of practical applications in frequency conversion, spectroscopy and communications.